This invention is in the field of injection molding and associated tools. In E. W. Mold and Tool Company, Inc.'s two prior U.S. Pat. Nos. 3,473,197 and 3,816,047, there was disclosed an injection mold assembly for forming a thin walled multi-partitioned container, such as a battery case. The male portion of the mold included a plurality of upstanding cores spaced apart to form the battery case interior partition walls. Movement of the cores during the high pressure injection step was controlled by means of a plurality of wedge shaped members extendable along the longitudinal axis of the battery case between adjacent cores holding the cores apart. Use of such wedge shape members resulted in the formation of ridges within the case along the interior surface of the bottom wall of the case. The two aforementioned patents further disclose locking members abuttable against the two opposite ends of the array of cores in a direction perpendicular to the longitudinal axis of the battery case preventing the cores from moving outwardly.
Additional locking members have been designed to further control movement of the array of cores. In E. W. Mold Company, Inc.'s U.S. Pat. No. 4,278,417 and its allowed U.S. patent application Ser. No. 705,130 now U.S. Pat. No. 4,576,568, filed Feb. 25, 1985, there are disclosed different types of locking fingers moveably mounted on one core and extendable against an adjacent core. In U.S. Pat. No. 4,278,417, the interior locks mounted to the cores are provided in conjunction with locking members abutting the opposite ends of the array of cores without the wedge shaped members being provided which extend between cores. In the aforementioned U.S. patent application, the wedge shaped members extendable between the cores are disclosed along with the end locking members. Last, in U.S. Pat. No. 4,481,161, there is disclosed a pressure stabilized injection mold which includes the wedge shaped members extendable between cores along with the end locking members abuttable against the array of cores.
Changes to the design of the thin walled compartment, such as a battery case, have been instituted requiring new and improved injection molds. With the decrease in size of vehicles, less space has been allocated to receive a compartment such as a battery case. Thus, it is desired to shorten the height of the battery case necessitating resting the interior cells of the battery directly against the top surface of the bottom wall of the case. It is therefore necessary to provide a completely flat top surface of the bottom wall eliminating any ridges which previously were formed by the wedged shaped members extending between the mold cores. At the same time, it is also desirable to eliminate any interior locking members mounted on one core and extending against an adjacent core. Disclosed herein is an injection mold having an array of cores which not only includes locking members positioned against the two opposite ends of the array of cores, but which further includes, in combination therewith, a plurality of wedge-shaped locking members extendable between cores in a direction perpendicular to the longitudinal axis of the battery case and elevated from the bottom wall of the case.
It is also desirable to provide a battery case having an exterior hold down flange. Such a flange is formed immediately adjacent the bottom wall of the battery case and also adjacent the locking members extending between the cores. As such, the formation of the outwardly extending flanges interferes with the normal retraction of the locking members and the opening of the mold for the removal of the formed case. Disclosed herein is a mold having side locking members which are moveable to allow proper opening of the mold without interference with the hold down flanges.